Wilder, Membra)ious Walls of the Bra'ni. 203 



significance of apparently atelic portions of the brain is 

 insisted upon; that, in 18S7 {^Atucrican Assoc. Proceedings., 

 251, and American Naturalist., XXI, 913-917) , I based a 

 primary chissification of animals upon the presence of a cir- 

 cumscribed cavity (rieui'ocoele) in the central nervous system 

 (neuraxis); that, since 18S0, all vertebrate brains in the 

 Museum of Cornell University have been prepared with 

 special heed to these parts, and the method of alinjection or 

 injection of alcohol has been generally employed; finally, 

 that, in addition to the special students in the anatomical 

 laboratories, there is no member of even my general classes 

 in Physiology and Vertebrate Zoology w^ho has not learned 

 the meaning of the phrases endymal continuity and ccvlian 

 circumscription. 



METAMERISM OF THE VERTEBRATE HEAD. 



If anything were necessary to convince one of the strong 

 place the problem of the segmentation of the head has made 

 for itself in all branches of morphology, it would be afforded 

 by the large number of papers more or less directly concerned 

 with it read at the last meeting of the Anatomical Society 

 held in Munich during the present year.('). 



The paper by Zimmermann quoted is devoted to a dis- 

 cussion of the segmentation of the brain, and the conclusions 

 may be summarized as follows: 



In an early stage there appear in vSalamander on either 

 side of the medullary tube and in front of the first pro- 

 vertebra-rudiment eight similar dilations. In higher verte- 



179, 654, etc.; " The Relation of the Th.-ilamus to the Paracoele," Journal of Nervous and 

 Mental Diseases, July, 1889 ; and the articles in the " Reference Handbook of the Medi- 

 cal Sciences," Vol. Ill, 1889 



I C. VON KuHFFER, "Die Entwickelung der Kopfnerven der Vertebraten." 



Fkorief, •' Zur EntwickeUingsgeschichte der Kopfnerven." 



KlLLiAL, " Zur Metamerie des Selachierkopfes." 



Zimmermann, " Ueber die Metamerie der Wirbelthierkopfes." 



Gaupp, " Zur Kenntniss des Primordial-Craniunis der Amphibien und Reptilien." 



